Novel system for safety increase in Commercial Diving

oIntroduction/background The cooperation between the Italian National Research Council and the CNS international Commercial Diving Company allowed the development of an innovative methodology and the related equipment's to assist professional divers during the vessel Dynamic Positioning loss; this "not uncommon" accident may cause the uncontrolled shift of the bell/divers system that is dragged by the umbilical and/or possible severe umbilical interlocking. In these very dangerous situations it should be necessary the detachment of the diver from the umbilical. If the driver is not equipped by a rebreather as lifesystem, the survival breathable gas bottle should be generally sufficient to assure the diver life for minutes. The developed and patented system refers to a special umbilical connector between the diver helmet and the bell, connecting all the necessary tubes and communication & electrical cables and a special rescue cell to assure the diver reconnection to a breathable gas mixture reservoir for long time (hours), waiting aids and rescue. oMethods It has been realized a 3D solid model, for the preliminary design and some plastic mockups as aid in prototype mechanical development of the connector. The built prototype has been tested in working condition of 35 bar in a special humid Hyperbaric Chamber; the connector is made of bronze and plastic parts coupled by o-ring seals. The umbilical may be voluntarily disconnected by the diver by means of a self operated simple and reliable pneumatic or manual command. The survival open metallic bell is packed on a bottle pack, and it is opportunely inflated by the a thermal insulating gas mixture, assuring a confortable shelter of about 1.5 m3 of volume oResults The first test of the whole system performed in a controlled pool environment resulted very satisfactory both in term of acceptability by the divers and the operability of the system. oReferences: -Bedini R., Laurino M., Magrin A., Cini D., Micheletti F.: "Structure of umbilical for connecting a diver with a diving support ship and/or a diving bell", PCT/IB2015/052615 10/04/2015 -IMCA International Code of Practice for O?shore diving IMCA D014 Rev.2 Febr 2014 -IMCA Emergency Procedures: Provisions to be Included for Diving Bell Recovery -U.S.Navy Diving Manual rev6 15 April 2008